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TLS Online TPP Program

#Question id: 7186

In dictyostelium stalk and spore cell maturation depends on cAMP level. Which of the following statement is incorrect regarding to this process?

#Unit 5. Developmental Biology
  1. During spore formation, ACG localizes to the spore surface when the prespore vesicles fuse with the plasma membrane. The cAMP phosphodiesterase RegA also plays a crucial role in regulating intracellular cAMP levels.
  2. This process is mediated by socalled sensor histidine kinases/phosphatases which either phosphorylate or dephosphorylate themselves on a histidine residue when a signal molecule binds to their sensor domain.
  3. Ammonia inhibits the onset of fruiting body formation and stalk maturation, activates the histidine phosphatase activity of sensor histidine phophatase C (DhkC), resulting in RegA activation, hydrolysis of cAMP and inhibition of PKA activity.
  4. Spore differentiation factor 2 (SDF-2) activates the histidine phosphatase activity of DhkA (histidine phosphatase A), which results in the inactivation of RegA, the accumulation of cAMP and in PKA activation, which subsequently causes spore maturation.
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TLS Online TPP Program

#Question id: 1397

#Unit 4. Cell Communication and Cell Signaling

The vertebrate equivalent of CED-9 is:
TLS Online TPP Program

#Question id: 1398

#Unit 4. Cell Communication and Cell Signaling

Which of the following properties is (are) characteristic of a benign tumor?

a. well differentiated              b. localized to tissue of origin             c. metastatic               

d. promotes angiogenesis        e. surrounded by a fibrous capsule
TLS Online TPP Program

#Question id: 1399

#Unit 4. Cell Communication and Cell Signaling

Loss-of-function mutations in which of the following genes typifies colorectal carcinomas?

a. myc              b. K-ras                       c. p53              d. APC
TLS Online TPP Program

#Question id: 1400

#Unit 4. Cell Communication and Cell Signaling

Which property is shared by malignant tumor cells and transformed cells in culture?

a. reduced growth factor requirement                        b. attachment-dependent growth

c. loss of actin microfilaments                                    d. altered morphology
TLS Online TPP Program

#Question id: 1401

#Unit 4. Cell Communication and Cell Signaling

Which of the following are proto-oncogenes?

a. fos               b. myc             c. p53              d. ras               e. Rb
TLS Online TPP Program

#Question id: 1402

#Unit 4. Cell Communication and Cell Signaling

Which of the following oncoproteins possess(es) protein kinase activity?